It seems like the first flowers of the season are on short stalks, then later the stalks become longer. If I were Darwin, perhaps I'd expect to find two different pollinators, one for each length of flower stalk.
And too, I believe I only have one clone of this species -- I don't know if more than one clone exists in cultivation, but I certainly hope so, and if so I hope someday to obtain other clones, to compare them with each other. I do have two clones of Pinguicula rotundiflora, one clone always produces flowers with a particular defect, and the other clone always produces perfectly formed flowers.